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  • 1
    Call number: ZSP-202-115
    In: Research report / Cold Regions Research and Engineering Laboratory, 115
    Description / Table of Contents: SUMMARY Between 1 July and 7 August 1960, the U.S. Army Snow Ice and Permafrost Research Establishment, Corps of Engineers, supported a £our-man glaciological expedition on the southern dome of the Greenland ice sheet. Measurements of snow temperature, density, ram hardness, and grain size were made at seven pit ~tudies along 191 mileS of over-snow traverse. In addition to the pit studies, 38 Rammsonde profiles were measured and 166 shallow pits were dug to measure temperature in the first meter of snow. The annual accumulation of snow was found to decrease westward, from 97 em water equivalent 50 miles from tP.e east coast, to 40 em 80 miles from the western margin. A possible precipitation shadow was encountered immediately west of the crest line of the ice sheet. The precipitation shadow and the decrease in accumulation westward indicate that the source area for the precipitation lies to the east of the southern dome, in the. Greenland Sea. Temperature profiles in the firn indicated that summer warming was still in progress. During August, melting at an elevation of 2000 m above se~ level was intense (OC in the top 75 em} •. According to the facies classification of glaciers (Benson, 1959, 1960}, most of the study area is in tfie percolation facies, with the possible exception of the westernmost· s.tation (mile l-138) which is at or near the saturation line. The daily heat exchange in the first meter of snow, near the time of maximum melt conditions, is between 20 and '35 cal/cinZ. This is approxi-mately 25o/o of the heat necessary to raise the temperature of a column of firn of unit cross Section and 1 m deep to the melting point. Effective values of thermal conductivity and diffusivity as determined from the temperature curves with no attempt made to isolate radiation and con-vection are, respectively, 4-6 x 10-3 cgs and 20-30 x 10-3 cgs. Radiation and convection in the first meter of firn cause "effective conductivity" values to be 4 to 7 times greater than the value k = 0. 0068pZ given by Abel's (1892), which is the conductivity at greater depths.
    Type of Medium: Series available for loan
    Pages: v, 22, A4, B1 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 115
    Language: English
    Note: CONTENTS Preface Summary Introduction Method of investigation Location Pit studies Temperature Hardness Density Stratigraphic measurements Thermal studies Stratigraphic features Grain size Grain shape Crusts Discussion of results Temperature Altitude gradient Latitude gradient Depth-density relationship Depth-load relationship Densification Stratigraphic analysis Facies relationship Climatological aspects 1960 meteorological observations Temperature Wind Barometric pressure Radiation Cloudiness Visibility Thermal studies Summary and conclusions References Appendix A Appendix B
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  • 2
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-202-112
    In: Research report / Cold Regions Research and Engineering Laboratory, 112
    Description / Table of Contents: Summary: The age hardening of artificially and naturally compacted snow has been investigated at the South Pole. Results show that the age-hardening process is greatly retarded at low temperatures. Artificially compacted samples of density 0.55 g/cm^3 attained a compressive strength of less than 3.0 kg/cm^2 after one year's aging at -49°C. Exposure to solar radiation accelerated the age hardening. Irradiated samples attained a strength of 6.0 kg/cm^2 after 100 hr, increasing to a virtual maximum of 8.0 kg/cm^2 at 600 hr. Compressive strengths increased witha decrease in snow-particle size and with an increasing angularity of the particles. Below 3 m the strength of naturally compacted snow was found to increase rapidly with an increase in density. Naturally compacted snow of density 0.55 g/cm^3 possessed considerably greater strength than any of the age-hardened samples of artificially compacted snow of the same density. Thin-section studies show that age hardening can be correlated with the formation and growth of intergranular bonds, and that bond growth falls off rapidly with decreasing temperature. In view of the low strength found in both naturally and artificially compacted snow at the South Pole, "cut-and-cover" undersnow camp construction may not prove practical at the South Pole.
    Type of Medium: Series available for loan
    Pages: v, 19, A6 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 112
    Language: English
    Note: CONTENTS Preface Summary Introduction Previous work Experimental methods Experimental results Series A Series B Series C Series D Series E Discussion Conclusions References Appendix A
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  • 3
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    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-202-108
    In: Research report / Cold Regions Research and Engineering Laboratory, 108
    Description / Table of Contents: Summary: The theory of snow densification is further developed on the basis of an exponential relation between viscosity and density. A linear relation between load-stress and strain rate is not valid for high stresses, and is replaced by a hyperbolic sine function. An empirical function is given for the temperature cycle correction. Two equations are derived for calculating depth-density curves with computers, and a simplified one for use with desk calculators. Instructions are given for determination of function parameters from field data. Four depth-density curves for Greenland and Antarctic locations are computed and graphed to show that the theory is useful.
    Type of Medium: Series available for loan
    Pages: iv, 18, A3, B5 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 108
    Language: English
    Note: CONTENTS Preface Summary Introduction Notation Stress analysis Analysis of densification process Non-Newtonian densification Equation for hyperbolic sine densification law Determination of parameters Discussion Glaciological engineering aspects References Appendix A: Example of calculation Appendix B: Snow density profiles
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  • 4
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-202-110
    In: Research report / Cold Regions Research and Engineering Laboratory, 110
    Description / Table of Contents: Summary: Nafe's (1957) presentation of reflection and transmission coefficients at a solid-solid interface was used to compute tables for the case of ice in contact with another solid at a plane interface. Energy ratios of all the combinations of reflected and refracted plane P and S waves were computed for 30 different cases of the second solid. A compressional velocity of 3.6 km/sec, a density of 0.9 g/cm^3, and a value of 1/3 for Poisson's ratio were assumed for the ice. For the other solid, the velocity ranged from 1.2 to 6.0 km/sec, the density from 1.5 to 3.0 g/cm^3, and Poisson's ratio from 0 to 1/3. The computations were carried out with an electronic computer, and the results are presented graphically.
    Type of Medium: Series available for loan
    Pages: iv, 17 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 110
    Language: English
    Note: CONTENTS Preface Summary Introduction Definitions Computation Results
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  • 5
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-202-109
    In: Research report / Cold Regions Research and Engineering Laboratory, 109
    Description / Table of Contents: Summary: The present paper contains a critical study of a number of foundation models suggested by various investigators, as well as a further development of some of the ideas involved. It is found that the model by Pasternak is the most natural extension of the Winkler foundation. It is also shown that the "non-solvability" of the problem of a finite bean or plate resting on a continuous foundation as posed by Wieghardt and further elaborated by Pflanz is not correct, and that problems of this type are solvable for any load distribution permissible in classical plate theory. The paper concludes with derivations of differential equations for plates resting on viscous and viscoelastic foundations, which may be used for solving problems involving compacted snow and permafrost bases.
    Type of Medium: Series available for loan
    Pages: iv, 15 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 109
    Language: English
    Note: CONTENTS Preface Summary Introduction The Hetényi foundation The Filonenko-Borodich foundation The Pasternak foundation Plates on a Pasternak foundation Visco-elastic Pasternak foundation Plates on visco-elastic foundations References Appendix A: Notation
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  • 6
    Call number: ZSP-202-111,2
    In: Research report / Cold Regions Research and Engineering Laboratory, 111,2
    Type of Medium: Series available for loan
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 111,2
    Language: English
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  • 7
    Call number: ZSP-202-111,1
    In: Research report / Cold Regions Research and Engineering Laboratory, 111,1
    Description / Table of Contents: Summary: Optical scintillation, visual resolution, and wind and temperature profiles were measured over snow, ice and frozen ground. The data were analyzed to determine relationships between (1) scintillation and visual resolution and (2) scintillation and meteorological and surface conditions. The experimental results included (1) estimates of the limit of visual resolution, (2) telephotometer measurements of the apparent fluctuations in brightness (scintillation) of an artificial light source, and (3) measurements of wind direction and of the vertical distributions of wind speed and temperature. The optical path was 543 m long and 1.5 m above uniform horizontal surfaces. All scintillation and meteorological data are given in an appendix. The principal results of the analysis showed that for turbulent flow in stable stratification over snow (1) visual resolution deteriorated systematically as scintillation increased in intensity and (2) scintilliation intensity increased with increase in vertical temperature gradient. Scintilliation was at a minimum in the absence of thermal stratification and at a maximum (in very stable thermal stratification) during the sudden transition from laminar to turbulent flow. For a given temperature gradient, scintilliation increased with increase in wind speed. When wind and temperature gradients were combined in terms of the Richardson number and related to scintilliation, the data obtained over snow indicated a critical Richardson number of about 0.35. Scintilliation power spectra for eight periods revealed characteristics that could be related to visual resolution, the Richardson number and the mean wind speed component normal to the optical path. NOTE: This file is large. Allow your browser several minutes to download the file.
    Type of Medium: Series available for loan
    Pages: iii, 32, A17, B44 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 111,1
    Language: English
    Note: CONTENTS Preface Page Summary Introduction The problem Previous work Plan of the investigation Conclusions Visual resolution and scintillation Visual resolution and wind, temperature, and surface conditions Visual resolution and height and length of optical path Results Measurements Analysis and discussion Visual resolution and scintillation relationships Scintillation and micrometeorological parameters Index of refraction fluctuations Scintillation and the temperature profile Scintillation and average wind speed Combined effects of wind speed and temperature gradient Scintillation and surface roughness Scintillation power spectra Scintillation and path length References Appendix A: Equipment and procedures Appendix B: Micrometeorological and scintillation data
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  • 8
    Call number: ZSP-202-100
    In: Research report / Cold Regions Research and Engineering Laboratory, 100
    Description / Table of Contents: From the Summary: During the summer of 1960, observations were made of ground fog on the Greenland Ice Cap and of sea fog in the Thule area in northwestern Greenland. A microscope-stage-fog impactor was designed, and its collection efficiency determined both empirically and by computation from the theoretical work of Langmuir and Blodgett (1946). The empirical efficiency was found to be considerably greater than the theoretical efficiency.
    Type of Medium: Series available for loan
    Pages: iv, 13 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 100
    Language: English
    Note: CONTENTS Preface Summary Introduction Method Design and operation of the impactor Collection efficiency Computation from theoretical values of Langmuir and Blodgett Empirical values Observations and results Fog on the ice cap Sea fog near Thule Discussion Conclusions References
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  • 9
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-202-105
    In: Research report / Cold Regions Research and Engineering Laboratory, 105
    Description / Table of Contents: Summary: A principle of particle segregation by freezing is presented. It is demonstrated experimentally by using a transparent freezing cabinet in which a sample of distilled water freezes from the bottom upward. In this way the freezing front line travels vertically and the particles are carried against gravity. By using the same material with different shapes (glass beads and broken quartz or glass) it is demonstrated that an important factor in particle migration is the shape of the particle or its contact area with the interface. By testing other materials with different shapes and sizes, it is demonstrated that another important factor is particle size and rate of freezing. Fine particles migrate under a wide range of rates of freezing; coarser ones migrate at lower and more limited ranges of rates of freezing. It is suggested that, for determining frost behavior of soils in permafrost regions, freezing from the bottom upward is a more reliable test than freezing from the top down. Freezing from the bottom more closely approximates freezing of the active layer above permafrost; also, friction with the cylinder testing wall is eliminated. The implication of this principle in engineering and studies of soil genesis in cold regions is emphasized.
    Type of Medium: Series available for loan
    Pages: iv, 8 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 105
    Language: English
    Note: CONTENTS Preface Summary Introduction Experimental procedure Experimental results Conclusions and recommendations References
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  • 10
    Series available for loan
    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-202-107
    In: Research report / Cold Regions Research and Engineering Laboratory, 107
    Description / Table of Contents: Summary: The formation of lake ice was studied during the winter of 1956-57 at Post Pond, Lyme, N. H. Tabular, columnar, granular, and crenulate textures of 36 blocks of ice observed are discussed in terms of relative growth velocity and shown in a classification chart. Ice structures are characterized by Forel striations, Tyndall figures, bubbles and strain shadows. Average crystal areas increased with ice thickness, the rate of increase being greater toward lake center, and ceased to enlarge when in a continuous bubble layer. The lake-ice sheet grew both from top and bottom, .downward growth resulting from crystals in a favorable vertical orientation of a-axes and upward growth coming about by water flowing on the original upper ice surface and freezing. Exception to this type of growth was found in the lake area which froze first, where individual crystal areas were larger at the surface and there was no upper surface ice accretion. Fabric diagrams of ice outside the anomolous area show a change of optic axis orientation from a high percentage of c-axes vertical near the surface to a high percentage horizontal at the bottom.
    Type of Medium: Series available for loan
    Pages: iv, 22, A2, B1 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 107
    Language: English
    Note: CONTENTS Preface Summary Description of the lake Cli rna te of the lake Methods of study Ice textures Crystal size Ice structures Crystal fabric studies Growth of an ice sheet References Appendix A: Weather data Appendix B: Sample data
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